The invention relates to a method and an apparatus for internally coating a metal tube, particularly a weapon barrel, with an electrically conducting layer.
In weaponry, efficiency-augmented ammunition causes, because of the high gas temperatures and flow velocities generated during firing, particularly in steel weapon barrels, significant erosions which wear out the barrel even before service-terminating metal fatigue sets in. It has been known to provide the inner face of weapon barrels with a hard chromium layer to prevent such erosions. Conventionally, the hard chromium is electrolytically deposited on the inner surface of the weapon barrel.
It is a disadvantage of the above-outlined conventional method that, among others, the electrolytically deposited hard chromium layers are very brittle and are not capable of withstanding the stresses caused by efficiency-augmented ammunition. Thus, significant erosion phenomena appear at barrel areas which consequently lose the chromium coating.